I've been gifted a pair of Thiel CS2s

I ran the same speakers for many years, in various rooms. Your room is too small. Perhaps something like Thiel's SCS's might work.

Oh maybe it's meters?? I haven't seen room of that size. It seems to be closet or some study or something in feet...
Really strange.

As long as you can sit about 8 feet away from the speakers, I you should be able to get pretty good imaging and phase coherency.

My friend used to run 2.4s and 3.7s in a pretty tiny room.

Having some room treatment helps too.

For those offering suggestions, he's been gifted the speakers so that isn't going to change. I'd still see if he can get a bigger room but 10 feet length wide still seems OK.

I own 3.6 Thiels and they like to sit into the room, so away from the back wall to provide good soundstage and image.

One needs to sit at least 8' from the speakers. The speakers need to be at least 1' from the walls and at least 3' from the corners.
The room has to be able to accommodate greater than 40 Hz bass extension.
IME, the Thiel CS 2's ported bass is a bit looser than most other Thiels, the high end can sound hard if they're toed in towards the listener. This room appears as though it could exaggerate those bass issues, and the nearness of the side walls practically demand toe in to avoid the early reflections that the Thiels wide sound-stage is likely going to aggravate otherwise.
Being nearly a cube, and being so small this room is going to be problematic with most speakers, but CS 2's will most likely highlight these issues.
On the other hand the Theil CS 2's with their 6 Ohm nominal, 5 Ohm minimum impedance, and 87 dB sensitivity are perhaps Thiels easies amplifier load (though IME the CS 2's sonic signature does require careful amplifier selection), and are reputed to be Thiel's most durable product ever.